Correlation effects during liquid infiltration into hydrophobic nanoporous mediums

Correlation effects arising during liquid infiltration into hydrophobic porous medium are considered. On the basis of these effects a mechanism of energy absorption at filling porous medium by nonwetting liquid is suggested. In accordance with this mechanism, the absorption of mechanical energy is a result expenditure of energy for the formation of menisci in the pores on the shell of the infinite cluster and expenditure of energy for the formation of liquid-porous medium interface in the pores belonging to the infinite cluster of filled pores. It was found that in dependences on the porosity and, consequently, in dependences on the number of filled pores neighbors, the thermal effect of filling can be either positive or negative and the cycle of infiltration-defiltration can be closed with full outflow of liquid. It can occur under certain relation between percolation properties of porous medium and the energy characteristics of the liquid-porous medium interface and the liquid-gas interface. It is shown that a consecutive account of these correlation effects and percolation properties of the pores space during infiltration allow to describe all experimental data under discussion

ELECTRONIC SPECTRA OF DYES MOLECULES ADSORBED ON SURFACE OF SILICA MODIFIED BY DENSE GRAFTING OF FLUORINATED HYDROCARBONS

Author Institution: St-Petersburg State Institute of Fine Mechanics and Optics, St-Petersburg, Russia; St-Petersburg State Institute of Fine Mechanics and Optics, Moscow State University, RussiaAbsorption spectra and fluorescence spectra of various dyes molecules have been studied for the case of adsorption on silica surface modified by preliminary grafting of fluorinated hydrocarbons. Comparison of obtained spectra of adsorbed dyes with the spectra of the same dyes molecules on nonmodified silica surface as well as on silica surface modified by grafting of hydrocarbons groups without atoms of fluor has been made. Diverse factors connected with discovered differences of these spectra are discussed. Influence of the density of grafting (degree of surface modification) and methods of deposition of dyes molecules on electronic spectra of adsorbed dyes are considered

NUMERICAL MODELING OF STEEL-AND-REINFORCED CONCRETE HYDRO TECHNICAL STRUCTURES

The method of FE modeling is presented for steel-and-reinforced concrete hydro technical structures. Real properties of material are taken into consideration

DETECTION OF ADENOVIRUS ANTIGEN BY A SURFACE-ENHANCED RAMAN SCATTERING ENZYME-LINKED IMMUNOSORBENT ASSAY

Aim. Study of the possibility of adenovirus antigen detection by recording of surface-enhanced Raman scattering (SERS) spectra of enzyme oxidized product of 3,3',5,5'-tetramethylbenzidine. Materials and methods. Clinical fecal samples containing adenoviruses, group A rotaviruses, noroviruses and healthy children samples, as well as laboratory strains of adenoviruses with a titer of 5 — 6 lg TCD50/ml were used. Sandwich immunoassay was used, the Raman spectra were recorded by a Raman spectrometer (532 nm) after incubation with silver nanoparticles. Results. The concordance of the adenovirus detection results was obtained in comparison with the enzyme immunoassay method with colorimetric detection and PCR. Conclusion. The possibility of TMB+ using as a SERS reporter and silver nanoparticles as a SERS substrate for the detection of adenovirus antigen in complex biological samples was shown

PHYSICAL-CHEMICAL PRINCIPLES OF THE PREPARATION OF HYBRID MATERIALS ON THE BASIS OF DETONATION NANODIAMONDS AS A NEW GENERATION DRUG DELIVERY SYSTEMS AND THEIR PROPERTIES

There were illustrated the main questions of development of new generation drug delivery systems as hybrid nanomaterials as follows: selection of nanocarrier, its standardization and the methods of immobilization of biologically active and medicinal substances. The basic organs of distribution and accumulation of advanced carbon nanocarrier - detonation nanodiamond were identified. It was shown that antihypoxic effect of the nanodiamond-glycine conjugate increased in comparison with a native Glycine and Mexidolum® as reference drugs